Editorial

Sinking feeling

Strict building codes can prevent sinkholes from forming in Pokhara Sinking feeling

Published at : February 21, 2014

Last November, the ground beneath parts of Aramala VDC in the Pokhara Valley began to give way, forming holes upto 5.5 feet deep and 20 feet wide. Fifty families were displaced by the appearance of the sinkholes, which prompted much head scratching from local officials and many attempts to appease the gods. Now, it seems the sinkholes have reappeared, this time larger and closer to human settlements. Last week’s rains seem to have prompted the reappearnce—sinkholes are formed when soil runoffs dissolve in water and react with limestone deposits in the bedrock to form cracks. Pokhara Valley, which rests on a bed of soft pervious minerals like limestone and dolomite, is especially vulnerable. The new sinkholes have put 250 families at risk of being swallowed up by the earth.

These sinkholes are a result of the ways in which humankind continues to plunder the earth. Unplanned urbanisation, massive deforestation and the rapid exhaustion of the water table all hasten and invite nature’s fury. Floods, landslides and sinkholes are predictable outcomes. But the power of nature is an unpredictable and unimaginable thing. Whenever an earthquake or a flood takes place, nature allows a glimpse into just what it is capable of—the very ground ripples like ocean waves and river waters sweep away all life and property in the blink of an eye. The same earth that houses the beauty of countless flora and fauna and the overwhelming majesty of limitless vistas is also its most dangerous and unpredictable force. And though nature is quite possibly the most perfectly balanced and ordered system to exist, it is also prone to undergoing regular and massive metamorphosis. The shifting of the tectonic plates and the upsurge of magma from the earth’s core are natural processes of change; they cannot be prevented, they can only be prepared for.

But the sinkholes in Armala were expected and could have been prevented. A 1998 study by the Department of Geology had warned that some areas of the Pokhara Valley were unsuitable for human habitation due to the fragile rock foundation. These very areas now support hundreds of homes and buildings. This kind of dangerous unplanned construction cannot be allowed to continue. Authorities must be serious about building codes and zoning laws. Areas known to be vulnerable to collapse must be left alone; to allow construction in such areas would be to knowingly put citizens in harm’s way. In the immediate, a critical assessment of the area must be conducted and vulnerable homes evacuated. Activities that increase risk, like stone and sand mining and deforestation, must be put to a stop. The state of Florida in the US—which also rests on a limestone base and thus, sees frequent sinkholes—has attempted a novel method inspired by the Ancient Egyptians, who built their pyramids out of mostly limestone. An

inexpensive process can treat the underground limestone and turn it siliceous, which renders it impervious to weak acidic solutions. Such a method can save lives and property but will require much dedication and investment.